The present invention relates generally to power supplies and more particularly to contactless, or wireless, power supplies.
Wireless communications are continuously being developed for numerous applications in the field of computing. For example, laptop computers are capable of communicating with remote servers through radio frequency (RF) transmission to access services such as the Internet or e-mail. Additionally, personal digital assistants (PDAs) are similarly capable of accessing remote services through RF transmission. Accordingly, physical wires or cords are not required with wireless communications, which results in significant advantages in terms of portability and minimal equipment required for continuous computing operations.
Although wireless applications in the field of computing are continually expanding, a wireless solution to the traditional power supply or xe2x80x9cbrickxe2x80x9d has not yet been developed. If a user is operating a laptop computer wirelessly from a remote location that does not have an adaptable power supply, i.e. 110V AC power outlet, the operating time of the laptop computer is limited to the available charge provided by at least one rechargeable battery, which is typically provided within the laptop computer. As a result, the amount of time that the laptop computer remains operational is limited by the life of the rechargeable battery when access to power via a power cord or xe2x80x9cbrickxe2x80x9d is unavailable.
One device that provides wireless power transfer is disclosed in U.S. Pat. No. 6,278,210 to Fatula, Jr. et al., wherein power is supplied to a rotary element by magnetic induction. Generally, a magnetic flux is introduced in an induction assembly, which causes an alternating current that is converted to a direct current, which is further stored in an electrical storage device without the use of wires. Unfortunately, the device of Fatula requires moving parts and is relatively large for use in portable devices such as laptop computers.
Accordingly, there remains a need in the art for a contactless power supply for use with computing devices such as laptop computers and PDAs. A need further exists for a contactless power supply that also provides battery charging capability for computing devices, furthermore onboard a mobile platform, e.g. a commercial airline, such that operating time of the computing device is not limited to the available charge of rechargeable batteries.
In one preferred form, the present invention provides a contactless power supply for use with a computing device disposed proximate a charging unit that comprises an inductive coil disposed within the charging unit and a receptor disposed within the computing device. Accordingly, the inductive coil provides electrical current, through its generation of a magnetic field, to the receptor to power the computing device and to further charge any rechargeable batteries of the computing device.
Preferably, the contactless power supply is employed on a mobile platform, e.g. a commercial aircraft, wherein the inductive coil is disposed in a seatback tray and a user simply places a computing device such as a laptop computer on the seatback tray in order to provide power for continuous operation. Additionally, the power supply may further provide battery charging capability to the computing device.
The contactless power supply may further comprise a shielding member disposed within the computing device in order to protect elements of the computing device from any detrimental effects of magnetic fields produced by the inductive coil. For example, the hard drive and any disk drives are preferably shielded to prevent contents therein from being inadvertently erased by the magnetic fields. Additional components of the computing device such as the internal clock, among others, may also be shielded as required, depending on the strength of the inductive coil.
The computing device according to the present invention may be a personal computer, a laptop computer, or a personal digital assistant (PDA), among others. Accordingly, an airline passenger or crewmember simply places the computing device on the seatback tray in order to have continuous power throughout the duration of the flight.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.